be sure about和make sure的意思和用法不同。make sure表示“弄确实；核实；查证”。be sure＋about+动名词或名词，意为“确信……”；“对……有把握”。make sure后可加从句或动词不定式，be sure about后只能加名词、代词或动名词。
I make sure I make time for fishing because it's how I de-stress。
我一定会腾出时间去钓鱼，因为这是我减压放松的方法。
It is impossible to be sure about the value ofland。
土地的价值是无法确定的。
Be sure to give your family my regards.
务必代我向你的家人问好。
No one knows for sure what hened.
谁也不知道究竟发生了什么事。
She seems very sure of herself.
她好像十分自信。
He is intelligent, to be sure, but he's also very lazy.
他固然聪明，但也很懒。